FunFacts App running error

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Did you know? "
    android:textSize="24sp"
    android:textColor="@color/colorAccent" />

<TextView
    android:text="Ants strech when they wake up in the morning"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:id="@+id/factTextView"
    android:textSize="24sp"
    android:textColor="@android:color/white" />

<Button
    android:text="Show Another Fun Fact"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/showFactButton"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true" />

// Declare our view variable
private TextView mFactTextView;
private Button mShowFactButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fun_facts);

    // Assing the views from the layout file to the correspondante value
    mFactTextView = (TextView)findViewById(R.id.factTextView);
    mShowFactButton = (Button) findViewById(R.id.showFactButton);

    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            //The button was clicked so update the fact TextView with a new fact
            String fact = "Ostriches can run faster than horses.";
            mFactTextView.setText(fact);

        }
    };

    mShowFactButton.setOnClickListener(listener);



}